Monthly Archives: July 2022

App note: General digitally controlled potentiometers

via Dangerous Prototypes

App note from Renesas on what are digitally controlled potentiometers and their operations. Link here (PDF)

Digitally Controlled Potentiometers (DCPs) brought about a new way to adjust resistance in analog circuitry. Mechanical Potentiometers were replaced by DCPs because of their ability to control resistance digitally using interfaces such as I2C, SPI, Pushbutton, 2-wire, and 3-wire (up/down). Unlike mechanical potentiometers where resistance is set by hand or a tool, the resistance of a DCP is communicated by an interface. This interface receives a value that is translated by the decoder from a binary to a decimal number, which sets the wiper into a corresponding position.

Name that Ware, July 2022

via Hacking – bunnie's blog

The Ware for July 2022 is shown below.

This is yet another fine ware contributed by jackw01. I kind of like how the board on the left went straight from bringup to production, without any attempt to strip out the debug headers or JTAG ports. Which is totally fine, btw: why change something that already meets spec, and might even be helpful with improving yields?…I just have to resist the urge to plug something into said ports.

Winner, Name that Ware June 2022

via Hacking – bunnie's blog

The Ware for June 2022 is a Cue COVID-19 test cartridge. Congrats to Nathan for identifying it first. Email me for your prize! Also thanks for the comment describing how it works, Frankie — that’s pretty fascinating. I’m copying your comment here so others who might have missed it can benefit from your insights:

The round object in the incubation chamber is a piezoelectric element designed to sonicate the sample solution. This ensures the contents of the lyophilized pellet (which contains the enzymes used for DNA amplification and detection) are well mixed with the sample solution. The PCB has heating elements which melt wax valves when it’s time to send the contents downstream. Lot of clever ideas in the Cue device.

I guess the blue stuff must be the wax valves. I was wondering what that was for. Also — wow, the black element is a mini sonicator. That is downright cool! Now I want to extract it from the plastic and hook it to a signal generator, heh.

Toe the 9DoF

via SparkFun: Commerce Blog

Hello everyone, and welcome back to another Friday Product Post here at SparkFun Electronics! This week, we are happy to bring you two new products that we really think you'll enjoy! First up is a new Qwiic 9DoF IMU Breakout. What? A new 9DoF? In this economy?! That's right, we built a board that utilizes both the ISM330DHCX and the MMC5983MA ICs, ignoring certain supply chain limitations in order for you to get back to single board movement sensors! Following that, we have a new take on a well known topic with the Machine Learning and AI Concept Kit. Let's jump in and take a closer look at this week's new products.

A little ingenuity never hurt anyone.

SparkFun 9DoF IMU Breakout - ISM330DHCX, MMC5983MA (Qwiic)

SparkFun 9DoF IMU Breakout - ISM330DHCX, MMC5983MA (Qwiic)

SEN-19895
$39.95

The SparkFun Qwiic 9DoF IMU Breakout combines the high-performance ISM330DHCX 3D digital accelerometer and gyroscope from STMicroelectronics with the highly sensitive MMC5983MA triple-axis magnetometer by MEMSIC to give you an ultra powerful and easy to use Qwiic enabled breakout board. Utilizing our handy Qwiic system, no soldering is required to connect it to the rest of your system. However, we still have broken out 0.1" spaced pins in case you prefer to use a breadboard.


Machine Learning and AI Concept Kit

Machine Learning and AI Concept Kit

KIT-20169
$89.95

The Machine Learning and AI Concept Kit is a starting place for working with predictive algorithms trained from historical data and inputs. With the Machine Learning and AI Concept Kit, you'll be offered an open-ended approach to machine learning and artificial intelligence, giving you countless options to make more project ideas come to life and enable you to process incoming data against ML-trained datasets.


That's it for this week. As always, we can't wait to see what you make. Shoot us a tweet @sparkfun, or tag us on Instagram, Facebook or LinkedIn. Please be safe out there, be kind to one another, and we'll see you next week with even more new products!

Never miss a new product!

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User Success Story: Caving with RTK

via SparkFun: Commerce Blog

The Search For Inexpensive and Portable Positional Accuracy As both a caver (a person who explores caves, often referred to as spelunking) for more than 30 years and an ambitious contributor to an open-source map project (OpenStreetMap (OSM)) since 2009, Eric Sibert has a long-standing passion for positional accuracy. In all that time, Sibert has been on a quest to find an accurate and portable tool that allows him to easily switch between these tasks - a quest that has proven to be not so simple.

To meet his requirements, he would need a tool that could be taken into remote caves, but also provide extreme accuracy for correcting street-level data. This dilemma ended up being a drawn-out and fruitless endeavor for quite some time. “I’ve been watching for years for potential GPS chips providing raw data at a low price. I made some attempts in the mid-2000s with the SiRF III chip.”

Click here to find out how Sibert finally found the product he was looking for.

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SparkFun RTK Express

SparkFun RTK Express

GPS-18442
$534.95
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The Plausibly Deniable DataBase (PDDB): It’s Real Now!

via Hacking – bunnie's blog

Earlier I described the Plausibly Deniable DataBase (PDDB). It’s a filesystem (like FAT or ext4), combined with plausibly deniable full disk encryption (similar to LUKS or VeraCrypt) in a “batteries included” fashion. Plausible deniability aims to make it difficult to prove “beyond a reasonable doubt” that additional secrets exist on the disk, even in the face of forensic evidence.

Since then, I’ve implemented, deployed, and documented the PDDB. Perhaps of most interest for the general reader is the extensive documentation now available in the Xous Book. Here you can find discussions about the core data structures, key derivations, native & std APIs, testing, backups, and issues affecting security and deniability.